Loren Williams at Fly Guys Outfitting provides a good tutorial on how to rig one or more nymphs as a dropper. The article highlights knots/tag ends (to attach nymph) and weighting considerations (no split shot/weighted flies) for strike detection.
Fishing, flies, flyfishing, Nymphing, Rivers and Streams
Fly fishing: Rigging Your Dropper Nymph(s)
SwittersB & Exploring 
Hi; By chance just landed at your site. What a GREAT site!! Great article on droppers. Keep up the great work, or should i say, keep up the great fun? I’ll be back. Cheers
LikeLike
I could go for a dozen of those sexy thangs, though it looks more like a king nymph than a prince.
LikeLike
Thanks for the addition…I guess a King Prince it appears.
LikeLike